Antisiphon trap



Nov. 21; 1933. H A, BLANCHARD 1,935,935

ANTI S IPHON TRAP Filed Feb. 13, 1951 Patented Nov. 21, 1933 UNITED STATES PATENT OFFICE ANTISIPHON TRAP llymen A. Blanchard, Bufialo, N. Y. Application February 13, 1931. Serial No. 515,492

3 Claims. (c1.1s2-'1) 4 This invention relates to improvements in waste traps of the class commonly referred to as antisiphon traps. A trap of this type is designed to maintain a liquid seal between the fixture to 5 which it is connected and the waste pipe by which the fixture is drained without the necessity of auxiliary venting means. f

In traps of this type, the practice heretofore has been to form the outlet chamber in such a 9 manner that the waste water is deflected away from the outlet of the chamber before passing therefrom or else it is caused to flow through a plurality of passages, and in some instances a combination of. these features is availed of.

The formation of the outlet chamber in the manner described is objectionable for the reason that obstructions are created to which solid materials carried in thewaste water may cling or adhere with the result that over a period of use the accumulation of such materials may impair or prevent functioning of the trap in the manner required.

Another feature of such traps which is also objectionable is the use of a common wall to separate the inlet and outlet chambers. The wall in such case, of course, projects into that portion of the trap which contains the liquid seal. In use, it is intended that liquid extend above the lower edge of this wall to a predetermined height and if there are not flaws in the wall and the seal is maintained at the correct height, the trap will function in the manner required. However, the

common practice in the manufacture of waste traps is to cast them and for this reason if there are any flaws in the dividing wall above the liquid seal the latter will be of no avail as communication will be established above the seal between the waste pipe and the inlet passage, and hence the fixture to which the trap is connected. It will, 40 therefore, be apparent that despite the desirable characteristics of so-called anti-siphon traps the objectionable characteristics attendant upon their use have been such as to practically offset the desirable characteristics and this to such an extent that they have in many localities been prohibited as failing to meet standard plumbing requirements. 5

The principal object of the present invention, therefore, is to overcome the objections above referred to which have existed heretofore in connection with the use of anti-siphon traps. while retaining their desirable features, this object contempl'ating a trap in which the outlet chamber is formed to permit direct passage therethrough of i the waste water in such a manner as to avoid possibility of accumulation of solid materials which are carried in the waste water.

A further objectis to providean anti-siphon trap which may be manufactured economically as a casting and which, by virtue of its construction may be readily examined and tested for flaws which result occasionally from the casting operations.

The invention is illustrated in the accompanying drawing, in which: Figure 1 is a vertical sectional view of a trap embodying the featuresof the invention." l Figure 2 is a section taken along line'2-2 'of Figure l. V

Figure 3 isasection similar to Figure 1 of a modified form of the trap.

Figure 4 is an end elevation of the same.

The invention is applicable to plumbing fixtures of various" types, the embodiment shown being merely by way of illustration.

In the embodiment illustrated in Figure 1, the trapeomprises a hollow body 10 formed with a threaded inlet opening 11, an outletchamber 12, a threaded outlet opening 13 and a well 14 through which the inlet opening and outlet chamber are so incommunieation. The trap preferably includes a pipef15 by which it may be connectedto the fixture with which it is to be associated, said pipe extending along side the vertical wall 16 of the body ,to provide an inlet chamber and being 35 threaded at its lower end for securement in the opening 11.

t will thus be apparent that the wall 16 is an exterior wall whichmay be readilyexamined for flaws created during the casting operations. 9 Such a construction has a decided advantage over a construction in which a common wall is employed between the inlet and outlet chambers' as in the latter case the wall is in reality an interior partition and the existence or non.- existence of flaws cannot be so readily determined; If a flaw, such as a pin hole, does exist above the level of the liquid seal in such a construction the seal of course, is of no avail and there is direct communication between the inlet and outlet chambers despite the seal. Instead of providing an inlet chamber by the independent pipe section 15 as described in connection with Figure l, the body of the trap may be designed to include an integral hollow vertical extension 15a, the latter providin the inlet chamber 16a. In this construction also, the vertical wall 16 of the inlet chamber is independent of the adjacent wall of the inlet chamber, the

latter being alcontinuation of the former.

The outlet chamber 12 (Figure 1) includes, in addition to the wall 16, a bottom wall. 17 and upper wall 18, the former curving in a sweep toward the side wall 19 leading to the outlet opening 13 while the latter extends in a. substantially horizontal plane toward the wall 19 and then upwardly toward the said outlet opening. The broad. sweep of the bottom wall 17 from the well 14 to the side wall-19 is for the purpose of insuring a scouring action of that portion of the outlet chamber during passage of the waste water through the chamber so as to prevent accumulation of any solid materials present in the waste water.

To this end, it is also preferred that the body of the trap curve in a sweep'from the wall 16 to the wall 18. Thus, the path provided through the trap for the waste water offers no sharp obstruction to which solid materials may cling. It is to be noted that the wall 16 of the outlet chamber terminates at its lower extremity 20 within the well 14, that is to say, below the bottom wall 17 of the said chamber. The side walls 12a of the body are preferably parallel (see Figure 2) and they cooperate with the walls 16, 17, 18 and 19 to provide a chamber which is greater in height than'in width, it being understood that the width of the said chamber is, however, greater than the distance between the lower end 20 of the wall 16 and the bottom of the well.

Duringdrainage of the fixture with which the trap is associated the waste water passes through the inlet extension 15 down into the well 14 and from the latter into the outlet chamber 12. In its passage through the outlet chamber apart of the waste water flows swiftly upwardly along the vertical wall 16 and thence along the top wall 18, thereby preventing the accumulation of foreign matter on the said walls while at the same time permitting the'waste water to flow rapidlythrough the said chamber. While waste water remains in the fixture, the inlet extension '15, well 14 and outlet chamber 12 are filled with the waste water and they remain filled until the fixture is empty. As the fixture empties the waste water begins to lower in the inlet chamber. At the instant the level of the body of liquid therein, reaches the loweredge .of the wall 16, the air following 'the liquid passes beneath the said .edge and passes in the general direction "of the outlet opening 13. By virtue of its density, the air rises upwardly and the contour of the outlet chamber facilitates its passage toward the outlet opening 13. Thusfthe path taken by the air is around a substantial body of the waste water, the greater part of which is moving along the bottom wall 17. Air passes through the trap .in this manner until the siphoning action isdestroyed, whereupon the water remaining in the trap flows by gravity back along the wall 1'? into the well 14 thereby returning any foreign matter which settles upon the said wall to the well and atthe same time providing. a liquid seal between the inlet and outlet chambers. The chamber 12 is designed so that the quantity of water retained is sufiicient notonly to fill the well 14 but to preferably extend a short distance above the bottom wall 17 of the outlet chamber. The well 14 is relatively small in capacity as compared to the capacity of the outlet chamber andit is principally because of this that the latter is capable of functioning in the manner described. p

'Not only is the liquid inpthe well'14 subjected to a siphoning action during drainage of the'fixture with which the trap is associated but it may be subjected to similar actions during the drainage of the other fixtures which are connected in the same system. Thus, as bodies of water from other fixtures in the system above it are discharged into the same waste pipe and rush by the outlet opening of the pipe with which the trap is in communication with the waste pipe, a vacuum is created in the discharge line between'the waste pipe and the trap. Hence, the air admitted through the inlet pipe 15 acts against the liquid in the well 14 and tends to destroy the seal.

, If desired a threaded opening 13a may be formed in the body of the trap to enable access to the well 14 and inlet and outlet chamber for the purpose of cleaning.

The path which the waste water takes through the trap is free of any obstruction such as caused by partitions or deflectors and sharp curves or corners are eliminated, thereby insuring self cleaning of the trap during drainage of the fixture to which it is connected.

In the embodiment shown in Figure 3 the in-' r let pipe 15a is formed integrally with the body of the casting and is formed with a lateral extension 22 by which the trap may be connected to a fixture and a threaded opening 23 by which access may be had to the interior of the trap for cleaning. The outlet opening 23a is formed in a lateral extension 24 and is in communication with the outlet chamber 12 through an out let passage 24. In other respects the trap is substantially of the same construction as the trap shown in Figure 1.

.I claim as my invention:

1. An anti-siphon trap including a body formed with a well and including an inlet which communicates with said Well and an outlet chamber which communicates at one end with said well and which is'formed at the opposite end and at the top thereof with an outlet, said chamber having a bottom wall which extends laterally from the top of said well and which curves in an upward sweep toward said outlet and a substantially, vertical end wall which extends into said well below the plane of said bottom wall, whereby to seal said inlet from said outlet chamber when the liquid in said well is at a level in the vicinity of saidv bottom wall, said outlet chamber being greater in height than in width and being formed to permit free passage of the waste water as determined solely by the exterior walls of said body,

said outlet chamber having a capacity sufiicient to permit by-passing of air around a body of liquid large enough to provide a seal in said wall, the side walls of said body which define the passagethrough said well and said outlet chamber being substantially parallel and occupying sub- 4 stantially the same planes substantially throughout their extent.

2. An anti-siphon trap including a body formed with a well and including an inlet which communicates with said well and an outlet chamber which communicates at one end with said well and which is formed at the opposite end and at the top thereof with an outlet, said chamber having a bottom wall which extends laterally from ward sweep toward said outlet and a substantially vertical, end wall which extends into said well below the plane of said. bottom wall, whereby of said bottom 'wall,'said outlet'chamber being the top of said well and which curves in an uprstantially parallel and occupying substantially the same planes substantially throughout their extent.

3. An anti-siphon trap including a body formed with a well and including an inlet which communicates with said well and an outlet chamber which communicates at one end with said well and which is formed at its opposite end and at the top thereof with an outlet, said chamber having a bottom wall which extends laterally from the top of said well and which curves in an upward sweep toward said outlet and a substantially vertical end wall which extends into said well below the plane of said bottom wall, whereby to seal said inlet from said outlet chamber when the liquid in said well is at a level in the vicinity of said bottom wall, said outlet chamber being greater in height than in width and being greater in width than the distance between the lowermost portion of said end wall and the bottom of said well, said outlet chamber being formed to permit free passage therethrough of the waste water as determined solely by the exterior wall of said body and being of at capacity sufiicient to permit by-passing of air around a body of liquid large enough to provide a seal in said well, said outlet chamber having a fiat substantially horizontal top wall.

' HYMEN A. BLANCHARD. 

